Storm Claudia Brings More Inundation to Portugal and Spain

The Iberian nations are again recovering from widespread flooding after Storm Claudia brought torrential downpours and strong winds over the past seven days.

The Storm's Genesis and Journey

This weather system developed from a region of depressed atmospheric pressure that had beforehand driven early season chilly and snowy weather through eastern parts of the Canadian territory and the American north-east at the start of November.

This storm journeyed east across the Atlantic in the middle of the second week of November before decelerating and halting to the north-west of the Spanish and Portuguese landmass, trapped within a trough of an progressively more wavy jet stream.

Consequences for Iberia

Spain's Galicia area in the northwest was the first affected, with a substantial 80 to 150 millimetres of rain pouring down along its western coastline in just a single day up to the evening of Wednesday as a sluggish front of rain crawled across the western sectors of the peninsula.

Additional rainfall and electrical storms on Thursday led to floods to areas in Portugal where a senior pair perished in the capital Lisbon after floodwaters from the swollen Tagus invaded their residence as they rested.

Tempestuous weather continued into the weekend, with a violent whirlwind devastating a outdoor lodging area and a close-by inn in the town of Albufeira in the Algarve region on the weekend's Saturday, claiming the life of an 85-year-old British woman and wounding 28 individuals.

Extended Consequences across the European continent

Claudia had more extensive impacts across western Europe. By siphoning heated air from the warmer regions, the system helped temperatures in southwestern France to nearly 30 degrees Celsius, the state's maximum ever November temperature.

By the following Friday, this tropical air mass clashed with a frigid air system across the northern regions of the continent, creating a band of rain running from the west of Ireland to the Russian Federation.

In the United Kingdom, this stalling band of rain produced very high rainfall totals, leading to severe flooding in the Welsh region.

As the storm loses strength in the coming days, the cold air mass will advance southward, providing the continent its initial glimpse of colder weather.

Simultaneous Occurrences in California

California underwent an "atmospheric river" recently, bringing heavy rain and powerful winds that led to rapid flooding and debris flows in regions impacted by forest fires previously in the year.

More than 50mm of rain was recorded in the southern region of the state on Friday, with a further 50mm widely across the state on the subsequent Saturday.

More than 100mm of rain fell over coastal parts of southern California in total, hitting 200mm overall in spots on high ground.

An atmospheric river is a concentrated stream of hot, humid air originating from the tropics or subtropics.

Regions previously burned including Palisades and Altadena endured the most severe the flash flooding and earth movements, prompting evacuations.

Across California, a man in his seventies lost his life after his vehicle was washed off a submerged bridge, and a child of seven years and her father were swept into the Pacific by big swells on the Central Coast.